Self-locking nut



Patented Dec. 21, 1943 SELF-LOCKING NUT v Edward J. Cole,.1eekskill, N.Y., assignor to Cole 1 York Machinery Mfg. Corp., a corporation of NewApplication September 2, 1942, Serial No. 457,026

4 Claims. (01. 151-21) This invention relates to a novel form of imvproved standard grip nut which may be readily and economically producedfrom all forms of standard nut blanks, together with a method ofproducing this form of binding nut.

The principal objectof the invention is the production of nuts of thegeneral type shown in my prior Patents No. 1,905,621, patented April 25,1933, and No. 1,966,613, patented July 17, 1937, although the presentnut is considerably simpler in structure and manufacture. In thisinstance, I am able to operate on conventional standard nut blanks ofany desired form and to flare the upper portion of the nut blank boreand consequently spread the crown portion of the nut without cutting orsplitting the crown, as disclosed in my prior patents.

Th resultant improved standard grip nut producedby this method isstandard in all respects, that is, the nubblank is conventional and,aside from the flaring and spreading step, the blank is tapped in aconventional screw tapping machine to form a standard thread thereinfollowed by a compression of the flared and spread parts, so' that theupper part of the threaded bore has threads of lesser depth than theremaining 1 threads.

Referring to the accompanying drawing:

Fig/1 is a top plan ofa standard hexagonal grip nut blank, although itwill be understood that the invention is equally adaptable for operationon square, wing, or other standard nuts;

Fig. 2 is a vertical section showing the straight bore through thestandard nut blank;

Fig. 3 illustrates the standard blank after the upper part of the borehas been flared and the upper portion of the crown spread:

Fig. 4 is asection disclosing the flared and spread ,standard nut blankafter it has been screw threaded or tapped on a conventional screwthreading machine;

Fig. 5 illustrates the two depths of the threads I which result fromreforming or compressing the blank after it has been threaded;

Fig. 6 is a top plan of the completed selflocking nut;

Fig. 7 is a side elevation of the completed nut illustrating itsstandard specifications; and

, Fig. 8 shows a completed square nut produced by the present method. a

Specifically, a standard nut blank I of anydesired size, shape, type,form or configuration is bored, punched, or otherwise cut, to form astraight-sided bore 3 therein, after which the bored nut blank isprocessed to flare the upper portion'5 of the bore 3 and to spread the.upper portion of crown l of the nut blank, as shown in Fig. 3. Thisflaring and spreadingmay be accomplished in any desired manner, eithermanually or by passing the blanks through amaghine of the characterdescribed and claimed in my copending application, Serial No. 447,267,filed June 16, 1942. After the flaring and spreading operation, theblank I is screw threaded throughout the length ofthe bore and, due tothe outward flare 5, the screw threaded portion 9 coincident with thelength of the flared part 5 is of lesser depth than the lower screwthreaded portion H, where the bore .is the same diameter as theoriginally formed bore.

As shown in Fig. 4, the base line of the thread throughout the entirebore is in a vertical plane while the crest line of the thread is in avertical plane throughout the unflared portion of the .bore and followsthe flare line in the flared portionoi the bore. It will be observedthat the crest of the thread in the unflared portion is a continuoussharp line oredge and the crest of the thread through the flared portionis progressively wider as the flare becomes more acute toward the crownof the blank.

Fig. 5 illustrates the threaded blank after the side walls thereof havebeen recompressed to place the exterior of the nut blank in identicalform and size to the original blank disclosed in Fig. 1, and here thelesser depth of the screw threaded part 9 is clearly indicated incomparison to the greater depth of the threaded part II in the unflaredsection of the bore.

After compression, the baseline of 'the thread in the unflared portionof the bore remains in a vertical plane while the base line in theflared portion assumes a similar form to that previously maintainedby'the flare. The crest line of the thread of the completed andcompressed nut is then in a vertical plane throughout the entire bore. z

After the standard blank nut with its flared crown portion has beentapped with a standard thread and the flared portion compressed tostandard dimensions the finished nut is applied to a standard threadbolt with the result that the full threads of the bolt binds at the baseof the less than full thread in the crown portion of the nut and thustakes up all looseness or play therebetween and flimlygrips the threadedbolt. This formation also permits the flare and compression to vary whennecessary to give an inthe completed grip nut after it has been operatedupon through the several method steps heretofore described and it willbe appreciated that the exterior configuration is identical to aconventional standard screw threaded nut. In

.Fig. 8 a similarly completed standard four-sided bo e being ofgradually decreasing depth with t to the remainder of the thread and thecrest line of the thread throughout the nut being in a vertical plane,said thread being uninterrupted throughout its length.

2. A grip nut comprising a standard nut blank wherein the depth of thethread throughout the major portion of the blank bore is of standard S.A. E. specification and the thread through a minor portion thereof is ofgradually decreasing depth, the crest line of the thread throughout thebore being in ayertical plane, said thread being uninterruptedthroughout -its length.

I 3. A grip nut comprising a standard nut blank having a continuouscentral screw-threaded bore therethrough, said thread beinguninterrupted throughout'its length and its depth adjacent the crown ofthe. nut blank being gradually shallower than the remainder of the screwthread, said thread being of uniform pitch throughout its entire length.

4. A grip nut as set forth in claim 3 wherein the diameter of the boretaken on'the crest line thereof is uniform throughout the bore.

EDWARD J. COLE.

